On March 23-25, 2012, AKB48 and its sister groups – including the soon-to-be-disbanded SDN48 - all came together for a three-day event at the Saitama Super Arena. Already one of the largest events in AKB48 history, the real surprise came on the final day when popular AKB48 member Maeda Atsuko announced on the stage that she would be graduating from AKB48.